A broccoli product sold at Walmart in Michigan was under recall. Now the FDA says the product may be considered deadly. Here's what to know.

The U.S. Food and Drug Administration upgraded the classification of recalled broccoli sold at Walmart originally issued in December to its highest recall category, according to the agency’s updated report.

Bags of broccoli florets that were sold at Walmart stores in 20 states are affected by a Class I recall due to concerns over possible listeria contamination.